posted by lisa .
The height in feet of a rocket after t seconds is given by h(t) = 160t - 16t2.
Find the maximum height the rocket attains:
After how many seconds does it reach this height?
-16x^2 + 160t
The max. point on the parabola is the vertex:
t = Xv = -B/2A = -160/-32 5 s
hmax. = Yv = -16*5^2 + 160*5 = 400 Ft.